Fix dynamic dom-bind template importing for Safari
Fix dynamic dom-bind template importing for Safari

- Fixes `Polymer::Attributes: couldn't decode Array as JSON`
- Fixes `addEventListener` on undefined nodes in Polymer `deserialize`

Fixes #4
Replaces workaround from polymer/polymer#2157

Neovici/cosmoz-page-router,Neovici/cosmoz-page-router,Neovici/cosmoz-page-router